File of U.S. Representative Grimm talking to reporters outside his office on Capitol Hill in Washington

NEW YORK (Reuters) - This fall, when Representative Michael Grimm asks New York voters to send him to Washington for a third term in Congress he may be splitting his time between the campaign trail and a courtroom where he is due to face tax evasion charges.

Grimm, a Republican and former FBI agent who represents parts of the city's Staten Island and Brooklyn boroughs, was indicted in April on charges of fraud, perjury and conspiracy tied to his restaurant, Healthalicious.

Last week, prosecutors asked a federal judge to start his trial in October, weeks ahead of the Nov. 4 election.

But a flurry of headlines about his business dealings is just one of the problems facing Grimm, who hails from one of New York City's rare Republican-leaning districts.

He was caught on camera in January threatening to throw a reporter off a balcony in the U.S. Capitol, saying: "I'll break you in half. Like a boy."

Grimm is far from the first U.S. politician to seek re-election under a legal cloud. But his behavior has turned off some voters who supported him in 2012, including attorney Harold Weinberg, 56.

"It's disturbing that a politician thinks he's above the law," Weinberg said while riding the Staten Island ferry to Manhattan. Calling the threat to the reporter "equally disturbing," Weinberg said he was unlikely to vote for Grimm in November.

Grimm's opponent, Democrat Domenic Recchia, Jr, a former City Council member, has jumped on the tax issue.

"Hard-working men and women ... deserve a congressman they can be proud of, someone who isn't so preoccupied with defending himself in court that he neglects the people he swore to represent," Recchia said in a statement.

Grimm, who denies the charges, declined to comment.

LOW EXPECTATIONS AND "BAD" BEHAVIOR

Other voters said they were inclined to overlook the criminal trial and the threatening outburst, saying they admired the compassion Grimm showed after the devastation in 2012 from Superstorm Sandy, which killed 24 people on Staten Island.

"Elected officials are called to a higher standard. It's never right. But they're human," said Jennifer Towles, a 61-year-old college fundraiser, who said Grimm had her vote for the third election in a row because of his storm response.

If history is any guide, many voters be equally forgiving.

Pennsylvania Representative Raymond Lederer won re-election in 1980 while facing a bribery indictment. Massachusetts Senator Ted Kennedy won re-election in 1970, and six more terms, after pleading guilty to leaving the scene of the Chappaquiddick Island car accident that left a young woman dead.

A sense of a personal connection by voters often trumps other factors, said Michael Genovese, a political science professor at Loyola Marymount University in Los Angeles.

"While Congress is unpopular as an institution, voters remain surprisingly loyal to their own member of Congress," he said.

Even if Grimm were to be convicted on the charges he now faces, he could remain on the November ballot - and serve in Congress. But he could face punishment in Congress, including the risk of being expelled, censured, reprimanded, fined or stripped of his House voting rights.

Politicians who have served time have been known to make comebacks.

Former Louisiana Governor Edwin Edwards, who spent six years in the House of Representatives and then eight years in prison for racketeering, is the front-runner in his bid to return to Congress, a recent poll shows.

Convictions can even give candidates a boost. South Carolina Representative Preston Brooks was a slavery advocate convicted of assault and re-elected in 1856. Voters seemed to like that he used his cane to beat up an abolitionist colleague.

Vermont Representative Matthew Lyon, convicted of sedition, won re-election from his prison cell in 1798.

"The public has such low expectations of government in general, and Congress in particular, that a congressperson doing something 'bad' isn't really new information and therefore not damaging," said Justin Holmes, an assistant professor of political science at the University of Northern Iowa.